Fixed position of Grayscale on Firefox + Translation + no background + Closing

Great WordPress Plugin!
(Test on WP 4.9.6)

I have found only 4 points to make it even better:
1.) If I use the Grayscale option, the menu position is not fixed when scrolling on Firefox 60.0.1 - 64 Bit
(All others hold the fixed position. And the problem does not occur on Google Chrome or Microsoft Edge.)
2.) "Reset" has no translation option (For example: "Zurücksetzen" in German)
3.) Light Background is good, but I miss an additional "No Backgroundimage" option to set ONLY the background to white (disable backgroundimage!) as in "Light background" BUT leave all foreground colours as original designed.
4.) Closing the menu with click on icon works, but ... additional closing options would be helpful.
a) "Close" / "Schließen" (GER) option in sidemenu OR an (X) button?
b) Maybe closing menu also by click on webpage? (That's what I intuitively tried before I found out that I must click on the icon again.)